#region Copyright

// The contents of this file are subject to the Mozilla Public License
//  Version 1.1 (the "License"); you may not use this file except in compliance
//  with the License. You may obtain a copy of the License at
//  
//  http://www.mozilla.org/MPL/
//  
//  Software distributed under the License is distributed on an "AS IS"
//  basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
//  License for the specific language governing rights and limitations under 
//  the License.
//  
//  The Initial Developer of the Original Code is Robert Smyth.
//  Portions created by Robert Smyth are Copyright (C) 2008.
//  
//  All Rights Reserved.

#endregion

using NoeticTools.StateEngine.Actions;
using NoeticTools.StateEngine.Exceptions;


namespace NoeticTools.StateEngine.Rules
{
    public class RuleBuilder<TContext, TStateEvent> : IRuleBuilder<TContext, TStateEvent>
    {
        private readonly IStateRules<TContext, TStateEvent> stateRules;
        private IAction<TContext> action;
        private ICondition<TStateEvent> condition;

        public RuleBuilder(IStateRules<TContext, TStateEvent> stateRules)
        {
            this.stateRules = stateRules;
        }

        public void AddAction(IAction<TContext> ruleAction)
        {
            action = ruleAction;
        }

        public void AddCondition(ICondition<TStateEvent> ruleCondition)
        {
            condition = ruleCondition;
        }

        public void Activate()
        {
            if (action == null)
            {
                throw new StateEngineRuleException("Rule is missing action.");
            }
            if (condition == null)
            {
                throw new StateEngineRuleException("Rule is missing condition.");
            }

            stateRules.AddRule(new StateConditionalActionRule<TContext, TStateEvent>(condition, action));
        }
    }
}